Gary Kovacs, CEO of the open source browser maker Mozilla, is worried that history might repeat itself.

In a keynote address here at the CTIA Wireless 2012 conference, Kovacs recalled the early days of the commercial Web, when AOL dominated both access and content and users were content -- even delighted -- to discover email, news, sports and other services and content within the dial-up firm's walled garden.

AOL's master stroke, as Kovacs recounted it, was to demystify the Internet for the mainstream consumer segment in the mid-1990s. At a time when the technology and its possibilities were unknown to most, AOL distilled the Internet into an easy-to-use, point-and-click affair that introduced users to a new way of receiving information and connecting with friends and relatives.

"When we're confused, we seek comfort. And when we seek comfort, we find comfort," Kovacs says.

But AOL's hegemony over the Web, as history records, was shortlived. To Kovacs, users were content with AOL's walled garden and dial-up service so long as it was all they knew.

But for advocates of open source, Mozilla prominent among them, the demise of AOL's walled garden was an object lesson that has a particular relevance for the next iteration of the Web -- mobile.

"The shift to open changed our world. And the shift to open also stands as a cautionary tale today," Kovacs says. "We don't like walls."

He argued that the online ecosystem is in the midst of another "momentous platform shift" as applications and services spread become more widely available -- and designed for -- mobile devices. But to Kovacs, the lesson from AOL suggests that the fissure between the winners and losers in the mobile era will be characterized by the extent to which device makers, content providers and others open their platforms to the developer community. He urged mobile firms to loosen the restrictive rules for developers that characterize apps marketplaces such as Apple's.

"I see a lot of walls going up again," he warned.

Kovacs described HTML 5 as the language of the open Web, urging firms to embrace its more than 3 million developers as they seek to spread their applications, content and services to the 2.1 billion mobile devices that fully support HTML expected to be in use by 2016.

"That will change the game," he said.

Then, too, mobile browsing is projected to account for more than half of users' collective Web activity by 2017, up from slightly more than 7% today. That puts the mobile Web in line for a growth spurt reminiscent of the rapid growth of the desktop Web.

Kovacs acknowledged that certain trouble spots continue to dog the HTML 5 on mobile, graphics and access to native APIs among them, but he expressed a devout faith that the developer community will work through them.

"Before we can realize this amazing future, we have a decision to make," he says. "Are we going to make history or repeat history?"

Kenneth Corbin is a Washington, D.C.-based writer who covers government and regulatory issues for CIO.com.